This invention relates generally to spinning wheels and more particularly to a spinning wheel flyer assembly adapted for level winding of yarn onto a bobbin during spinning.
The heart of a spinning wheel is its flyer assembly. As disclosed in Alden Amos, "Spinning Wheel Primer," 1976, a conventional flyer assembly in a manually-operated spinning wheel includes a flyer and a bobbin. The flyer comprises a spindle mounting a U-shaped member symmetrically connected to the base of the spindle. Conventionally, a row of hooks is distributed along one or both arms of the flyer to guide the yarn to a selected axial position along the bobbin. Alternatively, a single hook is mounted on a sleeve which is manually slidable along the arm. The spindle provides rotational support for the bobbin and includes an axial orifice in its base for introducing unspun fiber, such as wool, into the machine.
The flyer assembly is rotated to spin the fiber entering the orifice into yarn. The spun yarn is wound onto the bobbin, which rotates relative to the flyer to draw yarn through the hooks onto the bobbin. The bobbin draws the yarn outwardly through a radial opening in the side of the orifice structure and along one arm of the flyer, guided by the hooks. To wind yarn onto a different axial position along the bobbin, the yarn is shifted from one hook to another along the length of the arm.
It is desirable to wind the spun yarn onto the bobbin as uniformly as possible to get as much yarn on the bobbin before it is full and to facilitate winding the yarn off the bobbin into a skein after the bobbin is full. Doing so requires the spinner to periodically interrupt spinning in order to manually shift the yarn from one hook to another. A few highly skilled spinners can, by spinning at very high speed, cause the yarn to loop from one hook to another without stopping spinning. However, few spinners have this ability. For most spinners, it would be preferable to have some means for automatically level winding yarn onto the bobbin without having to interrupt spinning.
One attempt at poviding a level wind means is the level wind Ashford spinning wheel, disclosed in SPIN-OFF Quarterly Newsletter, page 2, December 1981. This machine utilizes a special mother-of-all or spinning head frame member designed to automatically shift the bobbin axially back and forth along the flyer spindle while the yarn feeds in through a fixed set of guide eyes. However, this system is complex, requires relatively radical and expensive changes to the structure of the spinning wheel and is vulnerable to breakdown problems.
Another approach to providing level winding means in a spinning wheel is disclosed in U.S. Pat. No. 2,623,347 to Bishop. Bishop's design propose a flyer assembly wherein a cross-threaded sleeve is mounted for rotation on one arm of the flyer. A traveler is threaded on the sleeve for axial movement back and forth, as the sleeve is rotated, to move an eye guiding the thread axially along the bobbin to level wind the thread onto the bobbin. The sleeve has a drive sheave mounted at one end which is driven by a pulley connected to a sheave freely rotatable on the spindle, positioned at the end of the bobbin opposite the orifice structure.
Although succeeding in level winding the yarn onto the bobbin, the structure proposed by Bishop suffers from several drawbacks. First, it cannot readily be used in the most common forms of spinning wheels. The flyer of Bishop is a rectangular wire frame structure closed at both ends and supported for rotation on a fixed spindle. The more commonly-used forms of spinning wheels utilize a flyer having a rotatable spindle and a U-shaped arm structure which is open at one end and connected to the spindle for rotation therewith. That is, the flyer arms and spindle are free at their ends remote from the orifice so that the bobbin can be easily removed axially from the spindle. Such arms do not provide the structural integrity to support a tensioned pulley drive at their free ends. And to close the free ends of the flyer arms would greatly impair the installation and removal of bobbins from the spindle. For similar reasons, the level wind flyer assembly of Bishop cannot be used in a single or dual drive bobbin-lead spinning wheel--its pulley and closed frame preclude directly driving the bobbin.
Another drawback of Bishop's design is that the level wind mechanism, requiring lubrication, rapidly gathers lint from the fiber being spun and thus requires frequent cleaning to prevent the threads in the sleeve from becoming plugged and rendering the level wind mechanism inoperative.
A further difficulty with the Bishop design is that constant tension must be maintained on the yarn during spinning to prevent the traveler from rotating with the sleeve and winding the yarn around the sleeve. This limitation prevents the level wind mechanism of Bishop from being used with the long draw technique of spinning. That technique is preferred for high-production spinning. Rather than applying steady tension to the yarn, the long draw technique calls for intermittently tensioning and then releasing long segments of yarn for winding onto the bobbin. Using this technique in the Bishop level wind flyer assembly would be disastrous. Apart from limitations on the spinning technique that can be used, the requirement that the yarn be continuously tensioned in the Bishop flyer assembly makes it more difficult for inexperienced spinners to learn to spin, because it adds another constraint to rather than simplifying the process of spinning.
Accordingly, there remains a need for an improved level wind mechanism for spinning wheels.